1. Field of the Invention
This invention relates to an electronic still camera for electrically recording an image of an object on a magnetic recording medium. More particularly, the invention relates to an electronic still camera in which an automatic white balance adjustment is carried out by sliding the lens cover which is integrally mounted on the camera body in such a manner that it can be freely opened and closed.
2. Background Art
Recently, an electronic still camera has been developed in which a solid image pickup element, such as a CCD, is combined with a small flexible magnetic disk or semiconductor memory, in order to record a still picture on the magnetic disk or semiconductor memory.
It is essential that, before an object is photographed with such an electronic still camera or video camera, a so-called "white balance adjustment" is carried out so that a white object is reproduced with true white color regardless of the spectrum of the light illuminating the photographic site.
Heretofore, for a silver halide film camera, during a printing operation at a developing laboratory the white balance adjustment is controlled, for instance, by controlling the red, green and blue exposure periods with yellow, magenta and cyan cut filters. Therefore, the photographer can photograph a scene without paying attention to the white balance adjustment.
However, in the case of an electronic still camera for recording still pictures directly on the magnetic recording medium, it is impossible to subsequently perform the intermediate correction of the white balance as described above. Therefore, the white balance adjustment is carried out at the time of recording or reproducing of still pictures. Generally, the camera is provided with a white balance adjusting mechanism so that the photographer can perform the white balance adjustment just before the still pictures are recorded.
For instance, in one example of a conventional white balance adjusting mechanism, a white object, such as a white sheet, is photographed in such a manner that its image covers the entire screen, or the mechanism is operated with white lens cap mounted on the lens.
In the case of a still camera, the photographer with the camera often moves to many places to photograph various objects. In this case, the photographer must perform the above-described white balance adjustment whenever he moves to a new place. However, if the white balance adjusting method using the lens can separately provided on the camera body is employed for the camera, the photographer is liable to forget to mount the lens cap on the lens although it should be attached to the lens whenever the photographic site is changed. That is, the photographing operation is liable to be performed under different photographic conditions with the lens cap disconnected from the lens. In this case, the photographing operation is carried out with the camera set for unsuitable photographic conditions. As a result, the recorded picture has unnatural color.